In a large-scale complex system, a management cost of the system is increasing. A manager of the system inputs various commands in order to carry out the management of the system, however, the manager who is not familiar with the system may not become aware that an input command badly influences the system. Then, when the input command is not appropriate, an error occurs in the system, and recovery operations or the like should be carried out for the system.
There is a technique for detecting a trouble by determining whether or not an event that occurs in the system matches definition manually registered in advance. However, according to this technique, when any event that has not been registered occurs, it is impossible to detect the trouble. Therefore, an operator cannot recognize that there is a possibility that the trouble occurs, and may carry out any operation that causes the trouble, erroneously. Moreover, because the event is manually registered, there is a problem that the load of the system manager is large.